Speed regulator



Jan. 6,1942,. E HOWARD I I 2,269,204

SPEED REGULATOR- Fild Nov. 9, 1940 4 Sheets-Sheet 1 v is w :4

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INVENTOR Jan. 6, 1942. G. E. HOWARD SPEED REGULATOR Fil ed Nov. 9, 1940 4SheetS-S heec 2 INVENTOR.

ATTORNEY SPEED REGULATOR Filed Nov. 9, 1940 4 Shee cs-Sheet s INVENTOR VAL; ma

Jan. 6, 1942. V G. HOWARD 3 3 SPEED REGULATOR Filed Nov. 9, 1940 '4 Sheets-Sheet 4 INVENTOR Patented Jan. 6, 1942 UNITED STATES PATENT OFFICE SPEED REGULATOR George E. Howard, Butler, Pa.

Application November 9, 1940, Serial No. 365,025

16 Claims. (Cl. 123-102) My invention relates to the control of engine speeds, including the control of automobile engines, as well as other types of gasolineand gas engines, steam engines, Diesel engines, and other types of prime movers.

The invention relates to the control of engine speeds, by the use of a suction-operated governor whose action or effectiveness is automatically modified to a degree that varies with changes in engine speed, somewhat after themanner de- .110 scribed in my application Serial No. 296,241, filed September 23, 1939 (Paltent No. 2,224,600), but is an improvement upon the invention of said application, as well as upon the combination of speed and suction-operated devices of my Patent- I It is characteristic of all Valves for controlling the input of energy, including combustible gas mixtures and slteam, that the rate of admission of motive fluid progressively increases with in- ZO type, that is, those having a governor piston connected to the throttle valve and the cylinder of the piston communicating through asuction line with the intake manifold, the speed at which the piston will be operated to open the valve, with consequent; addition to power, is greatest at light loads. This is because the suctional force in the intake manifold varies from 22" of mercury at 7 no load (valve closed) to 2" of mercury at full load (valve fully open). This condition is aggravated by the fact that at light loads any certain change in valve opening results in from 3 to 5 or more times the change inpower than is the case for a similar change in degree of valve opening at heavy loads. Therefore, in a speed regulator of this type, the change in power will be from 30 to times'as great at light loads as at heavy loads.

It follows that if the suction line and the area in the governor cylinder are properly proportioned for a correct range-of throttle valve movement at light loads, the valve-movement at heavy 50 loads will be too slow, thus causing a too great lag at heavy loads and resultant swing of the valve past the point at which it should come to rest. Conversely, if the suction line and governor cylinder capacity are properly proportioned for 5 heavy loads, they will overrun at light loads and swing back too far and too fast, thus causing fluttering.

In my saidapplication, I disclose meanscontrolled by engine speeds at and near the governed speed, for varying the efiectiveness'of the suctional force, which acts on the valve-operating piston, such means comprising the admission of atmospheric air or bleeding into the suction line :or the cylinder, whereby there is a fixed bleed area and consequently greater bleeding into the governing cylinder at light loads than at heavier loads, at any given speed. While such an .arrangement is superior to either governing devices operated only by suction, or speed governors such as those of the centrifugal type, I have discovered. that'a still greater accuracy ofcontrol can 'be secured.

To this end the present invention has for one effectiveness of sudtional force from anintake manifoldor the like upon a valve-operating piston isautomatically varied in"'predetermined relation to the position of the throttle valvefat' the time the sucltional force is brought into action to .move the valve.

Stated more broadly, my invention T provides forthe automatic grading of the 'rate and'extent of travel of an element that controls'the supply of motive fluid to a prime mover, so that the rate of motive fluid input will be so proportioned at any load as to effect a desired change of fluid supply to meet. a load change, without jerking or fluttering, preferably including the use ofa speed element that is wholly responsive to changes in engine speed and which is frictionless, so that a minimum time is neededyand a minimum speed change, to accommodate the rate or volume of fuel supply to load changes.

) Some of the form-swhich. my inventionmay take are shown in lthe. accompanying drawings wherein Figurel is a side view of an automobileengine equipped with my invention; Fig. 2 is a sectional view showing the governor piston of Fig. 1 and its operative connection to the throttle of its objects the provision of means whereby the r the said valve; and Figs. 6 and *7 show the application of my invention to two forms of Diesel engines.

As shown in Fig. 1, the apparatus includes various conventional parts such as an air cleaner 8; a choke valve 9; a carburetor It, a throttle valve II and a fuel inlet passageway [2 leading to the intake manifold I. A foot pedal [3 has link connection with a bell crank 14, that is in turn connected to a link that has connection with a rocker arm l6 which is loosely mounted on a shaft 11, that carries the throttle valve II, as shown more clearly in Fig. 2. It will be seen that when the foot pedal 13 is depressed, the link I5 will be thrust upwardly to rock the arm It in a clockwise direction upon the shaft H. A crank arm I8 is keyed to the shaft ll and carries a pin or stud l9 that extends across the rocker arm I6, as shown in Fig. 2. A tension spring 29 has connection with the crank arm I8 and is anchored to an adjusting screw 2 l whereby the tension of the spring 23 can be adjusted. When the arm i6 is moved away from the stud I9, through depression of the foot pedal, against the ftensional force of' a spring 22, the spring 29 will rock the shaft IT to move the throttle valve I l to its open position shown in Fig. 2.

Automatic movement of the throttle valve ll toward closed position, through suctional force created within the intake manifold at high engine speeds, is effected by suction created in a cylinder 23 to draw a piston 24 toward the right, the piston operating through a link connection 25 to rock the crank arm and the valve in a. counter-clockwise direction against the tension ofthe spring 20. This suctional force is exerted through a suction line 26 that leads to the intake manifold 1. The piston 24 operates against a compression spring 21 which can be adjusted by a screw 28 to vary the extent to which the piston will move under a given suctional force, and hence serve as one means for adjusting the governed speed point. 7

Fuel mixture at substantially atmospheric pressure is bled into the cylinder 23 to vary the effectiveness of the suctional force. This bleeding is through a pipe 29 that communicates through a valve 39 with a pipe 3| that leads to the intake line immediately below the carburetor ID, or which may lead from the air cleaner 8. In either case, substantially atmospheric pressure is admitted to the cylinder 23.

An important feature of the present invention and one wherein it differs from my said application resides in the fact that a small chamber 32 is provided on the wall of the cylinder 23, and the cylinder wall 23 is provided with a series of openings 33 that are progressively uncovered as the piston moves toward the position shown in, Fig.2, so that with a given rate of flow through the pipe 29 as regulated by the valve 30, to be hereinafter described, there will be freer flow into the cylinder 23 when the throttle valve H is in its open position than when the valve is adjacent to its closed position, the extent to which the ports 33 are uncovered depending upon the position occupied by the piston 24 and hence the position of the throttle valve H; A single long slot could be provided in lieu of the ports 33.

In Fig. 3 I show the manner in which the valve 34 within the valve chamber 39 controls flow through the pipes 29 and 3!. The valve 34 cooperates with a valve seat 35 and is operated by a solenoid 36 which, when energized, will lift the valve 34 to its seated position and thus cut 01f flow from the pipe 3| to the bleeder pipe 29. The solenoid may conveniently be supplied with energy from the car battery 31, the circuit being through conductor wires 38 and 39, and the line 39 being provided with switches 40 and 4|. Whenever the switches 40 and 4| are closed, the solenoid 36 will, of course, be energized and flow of bleeding air to the cylinder 23 thus cut off.

The switch 40 is actuated by a solenoid 42 that is connected through conductors 43, with a generator 44 that may be driven by a belt 45 from the engine shaft. When the engine speed reaches a predetermined rate, the generator 44 will develop sufficient energy to operate the solenoid core 46, which in turn flexes the springlike switch arm 40 to move it into engagement with the switch terminal 41 and hence completes the circuit through the solenoid 36, and causes closure of the bleed valve, so that the suction within the manifold I will be fully efi'ective to move the throttle valve H toward its closed position. The tension of the switch arm 49 can be adjusted by a screw 48.

In explanation of the provision for providing what is in effect graduated bleedthro-ugh the use of the cylinder ports 33, the bleeder valve 34 is usually in completely open position, so that there is a constant bleed to the governor cylinder 23, and the cylinder 23 is always in communication with the intake manifold. Assuming the throttle valve II to be nearly closed and the piston 24 in approximately its extreme righthand position, communication through the bleed ports 33 will be entirely or almost entirely out off, so that substantially the full suctional force of the manifold will be available to hold the piston 24 and to resist movement thereof toward the left under the force of the springs 21 and 29. Upon reduction in engine speed and consequent reduction in suctional force, the piston will be moved toward the left by the said springs, and the throttle valve consequently moved toward its open position, but in the initial stages of throttle movement toward open position, a small change in angularity of the throttle valve results in atnarked increase in power, as compared to the same angular change when the throttle is nearer to its fully open position. In order to prevent too rapid andgreat movement of the throttle from its nearly closed position, most of the port area at 33 is covered by the piston 23, so that the suction from the manifold will not be diluted so greatly by the bleed, and will therefore offer greater resistance to throttle opening force exerted by the springs 29 and 21.

However, when the throttle valve and the piston 24 are at about full-open position, as shownin Fig. 2, it is desired that the suctional force be rendered less effective so that valve H can be moved through a greater angle under a given change in suctional force that results through change in engine speed, and so that the change in fuel supply for a given change in speed will be approximately equal to the change in fuel supply that is effected upon such degree of speed change which may occur when the throttle II is nearer its closed position. To this end, an increased number of the bleed ports 33 are uncovered as the throttle valve H moves toward its fully open position, such arrangement permitting the'force of the springs 29 and 21 to be more effective in moving the valve against the suctional force and hence giving such valve a greater movement under a given change in suctionalfo'rce when it approaches its fully open connect" the control system, he will place his foot upon the plunger-50 toopen the switch 4|. and

position than is given-to the valve under a like changein engine speed and suctional force when the valve is nearer to its closed Position, where the suctional force more effectively counteracts the pull of the springs. I V

The use of the generator 44 and the solenoids 42 and 36, which elements are substantially frictionless as compared to speed governors of the centrifugal type, for example, contribute largely .to the avoidance of lag and overrunning, and to quick responsiveness of the governor at predetermined changes in speed. I make still another provision for effective quick changes of fuel sup-:

ply, in that there is a by-pass of fuel around the throttle II to the-intake manifold This bypass line consists of the pipe 3|, valve chamber 30, pipe 29, cylinder 23 and pipe 26. This arrangement provides in effect a two-stage fuel supply change, which may consist of an addition to the fuel which flows past the throttle H and under certain conditions will consist in cutting 01f or increasing the auxiliary fuel supply before the valve has been started toward its closed position or its open position, as the case may be. The valve 34 is more quickly responsive to load and speed change than is the piston 24, because of the inertia of the piston and its associated moving parts, so that for changes in load and speed, this valve-controlled by-pass serves to vary the rate of fuel supply more quickly than if said supply is controlled only by movement of the piston 24. The arrangement, therefore, reduces the time required for balancing load and fuel supply, in that there is less movement of parts and hence less time required for effecting the balance. The by-passing of the auxiliary fuel also softens or dampens the change from one condition of load and fuel supply to another.

While I desire governing apparatus of such form that there is quick responsiveness to change of speed, there are practical limits to the quickness and extent to which the throttle valve should be opened under speed changes. For example, time is required for carburetors to adjust themselves to a sudden and wide opening of throttle. Therefore, in Fig. 2' I have shown means for dampening or delaying the responsiveness of the throttle-operating piston 24. Thus, for example, {under heavy load changes, there will not be such sudden and instantaneous response of the piston 24 as will prevent the proper functioning of the carburetor. To this end I provide a reservoir 23a. that communicates with the cylinder 23, a valve 23b being provided for controlling the area of communication and hence the dampening effect.

The switch 4| is provided for the purpose of rendering the control apparatus inoperative to move the throttle valve II, in that when the circuit 3839 is deenergized, the valve 34 will be in fully open position, and sufiicient bleeding air thereby admitted to the cylinder 23, rendering the suction through line 26 ineffective to move the governor piston 24, except at very high speeds. By this means, the driver may in emergencies drive the car faster than at its normal governed speed. The switch 4| is secured to the underside of the accelerator pedal I3, as shown in Figs. 1 and 4, and is provided with a stud 50 that operates as a plunger through the pedal. The switch arm 4| is of spring-like material, and normally lies in closed position against the switch terminal 52, When the operator desires to dismay then operate thev car without being limited by theset governed speed. Althoughin that case the main bleed valve is 'fully open, at any desired speed limit such as at 65 milesperhour,

enou h suction will be created to move thepiston 24 against the springs'20 and 21. These springs, or one of them, will be adjustedto hold the pistonagainst the force of an unbled suction at 40- miles perhour, for example.,

The pedal |3 is also provided with a latch, lever 53 which is ofbell crank form and whose lower leg is movable intohooked engagement with a I by the governing apparatus and Without the necessity of holding his foot on the pedal l3, he will depress the pedal and then shift his foot sidewise off the latch lever 53, permitting it to engage the keeper 54- and, of course, take his foot. off the switch plunger 5|].v If he desires to operate the pedal l3, he need only place his foot on the latch lever 53, whereupon he can move the pedal up and down at will. Ifhe keeps his foot from the plunger 50, the governing apparatus will be effective to prevent excessive speeds."

A rheostat 55 is mounted on the panel board 55 of the automobile, in the line 43 which'leads from the generator 44 to the solenoid 42. This rheostat serves as a means whereby the o'perator can readily vary theeffectiveness of the solenoid at various engine speeds, and hence serves as a convenient means for adjusting the'rate of governed engine speed.

In the solenoid 35, the movable core which carries the valve 34 is normally held in its lower position, under the force of gravity, and will, of course, return to such position when the circuit 3839 is broken: While solenoidsand valves of from oil or grit at the core of the solenoid 36 or the valve 34. Therefore, since the core of the solenoid '36 does not have to be spring-biased and balanced, any desired strength of pull can be exerted and the problem of oil ordirt eliminated as a factor in speed control.

g It will be obvious that instead of the generator 4 thateffects operation of 'the'bleeder valves 34 or 6| when'the engine speed is toogreat, other speed devices such as a centrifugal governor or pump may be employed for operating the bleed valves, as disclosed in my said application.

Referring now to Fig. 5, I show an arrangement wherein a solenoid 58 is provided for operating a bleeder valve, said solenoid being energized and its circuit controlled in the same manner as the solenoid 36 of Fig. 3. The solenoid core 60 op- 62, communicates with the governor cylinder 83. The" cylinder communicates through a pipe 64 with the intake manifold of the engine, as in the case of the pipe 3| of Fig. 1.

The throttle valve 65 is spring-biased toward open position by a spring 66 and also may be operated manually in the same manner as is the throttle I I. The valve will automatically be moved against the tension of the spring 66 by the governor piston 61, but in this instance, the .bleed into the cylinder 63 will be regulated entirely by the valve 61. A link 68 connects the piston 61 with a slide bar 69 that carries a cam block I8. A cam roller II is carried by a camming arm I2 that is pivotally connected at 13 to a suitable stationary support. The arm I2 normally affords vertical support for the valve 6|, through the medium of an adjustable screw I4, the camming arm I2 and hence the valve BI being raised and lowered through movements of the piston 61 and the camming block I0.

When the engine speed exceeds a predetermined rate, the solenoid will effect complete closure of the valve 6|. which the solenoid operates will be determined by adjustment of a rheostat such as the rheostat of Fig. 1. However, at all other times the valve 6I will be partly open, the extent of opening being determined by the position of the piston 61. In '1 this case as in that of Fig. 2, when the piston 61 is in its right-hand position and the throttle valve 85 nearly closed, the bleeder valve 62 will also be nearly closed, so that the suctional force of the manifold upon the piston 61 will be sufficient to I.

prevent too great movement of the throttle by the spring 66. When the valve 65 is at a farther open position, the bleed valve BI will be lower than shown in Fig. 5, so that there is greater bleed and the spring 66 will be effective to move the valve 65 more readily under a given change of suction in the manifold than under the same degree of change in suctional force when the throttle valve is farther toward its closed position.

It will be understood that the contours of valve core 6| and the cam block 18, or either, may be changed so as to secure desired load and speed curves.

Referring now to Fig. 6, I show the application of my graded bleed device to 9. Diesel engine of f the four-cycle type, it being understood that, as in the case of the other figures, the showing is schematic and that the various parts are drawn to a size convenient for the purpose of clarity dispel exhaust gases, and an eduction valve 85 is provided to permit scavenging or exit of burned gases. These valves 8:; and 85 will be operated in any suitable manner well known in engines of this type.

A piston or pump 86 is periodically operated to force fuel oil into the cylinder 88, such operation being effected through suitable driving connections with the crank shaft 83.

As in the case of all Diesel engines of the fourcycl type, air is sucked past the valve 84 into the cylinder during a down-stroke of the piston 8I On the next up-stroke, this air is compressed to a high pressure and temperature. On the next The engine speed at I 2,269,204 erates a bleeder valve M which, through a pipe down-stroke, oil, which is supplied under pressure through a line 81, is-forc'ed by the pump 86 through spray holes 88 into the cylinder where it mixes with the hot compressed air and burns, thus supplying power to'force the piston down. A suitable check valve (not shown) is provided to prevent exploding of the combustible mixture in the pump chamber 89. During the next upstroke of the piston, the valve is opened to permit exhaust of the burnt gases. On the succeeding down-stroke, air will be admitted past the valve 84 and the various movements repeated.

I have shown the pump piston 86 as yieldably held inits raised position by a spring 9|. The pump piston, which also serves as a valve to cut off flow from the line 81, is forced downwardly by a rocker arm 92, whose inner end has engagement with the pump piston, and whose outer end is engaged by a bar 93 that is mounted in suitable guides, for vertically sliding movement. The bar is provided with a stop collar 94 that abuts against a fixed guide 95 to limit downward movement of the slide bar 93. A bracket 96 is mounted for vertically sliding movement in a guide 91 and has a pawl 98 pivotally supported thereon, the pawl being normally biased in a counterclockwise direction by a spring 89. The pawl normally has latched engagement with the lower end of the rod 93, so that when thebracket 96 is raised, the arm 92 will be rocked in a clockwise direction to move the pump plunger 86 down and force a fuel charge from the chamber 89 into the cylinder. The bracket 86 is periodically raised by a cam I8I which has suitable driving connection with the engine shaft 83, so that the cam will be given one rotation during each two revolutions of the crank shaft 83.

In order to regulate the fuel charge, I provide means for disengaging the pawl 98 from the rod 33 and thus reduce the amount of fuel charge when the engine speed is too great. To this end I provide a block I82 which has a beveled surface that cooperates with a similar beveled surface I820, on the pawl 98. The block I82 is carried by a slide rod I83 that is rigidly connected to a diaphragm I84, mounted in a case I05 which, when there is sufficient suction at the left-hand side of the diaphragm, will move the block I82 away from the pawl 98 a distance dependent upon the degree of effective suctional force at the dia phragm, and thereby control the tripping of the pawl 98, and hence the amount of fuel which is injected into the engine cylinder during a fuel feeding stroke.

A spring I86 that surrounds the stem I81 of a slide valve I88 urges the rod I83 in the direction indicated by arrow I89. The valve I88 operates in a valve chamber III that has an inlet chamber II2, which communicates through a series of ports II3 with the interior of the valve chamber II I, the chamber H2 and the ports II3 corresponding to the elements 32 and 33 of Fig. 2. A valve chamber I54, which corresponds to v the valve structureof Fig. 3 and is actuated by a drawn pastthe intake valve' 84 upon downstroke of the piston 8|. V

A suction chamber I20 is provided in theline H8, so that a suctional force will constantly be present in said line, notwithstanding that the valve 8'4.is periodically closed during upstroke of the piston 8|. A check valve I2I opens under suctional force in the line I I9, b'utwill close when flow through the "line II9 isinterrupted, thus preserving a condition of subatmospheric' pressure in the line I I8 during operation of the engine."

Thed'egree of suction at the left-handside of the'jdiaphragm I04Cis primarily dependent upon the suctional force in the pipe N9, the effectiveness of this force, however, being modified in accordance'with the position of the slide valve be cut off, thus increasing 'the'efiectiveness of the vacuum force.

The power of a Diesel engine is proportionate to the'pressure stroke of thepump 86, which may cut off the supply of fuel throughthe jets 88 at one-quarter stroke, one-half stroke, ifull stroke, or any desired fraction of a stroke. A small differencein cut-off at light load makes a greater power difference relatively than a similar difference in pump plunger stroke at a heavy load. Therefore, the rate of movement of the Wedge member I 02 should'be different at a light load than at a heavy load, in order to produce smooth running.

The extent of movement by the block I02 under the influence of spring I06 is limited by a stop shoulder I22 against which the inner end of the valve I08 abuts. It will be seen that when the cam ml 'is moving'the bracket 96 upwardly'in order to effect a pressure stroke of the pumppiston 86, a full fuel feeding stroke will besecured if the pawl 98 is not tripped out of engagement with the bar 93. However, if the suctionalforce in the diaphragm chamber I05 is at a low'point, the cam block I02 will'trip'the' pawl 98, thus releasing the plunger 86 to upward thrust under the pressure ofthe spring 9| and interrupting the injection of fuel The point at'which this interruption occurs depends, of course, upon the speed of the engine and hence the suctional force in the pipe II9. It will be understood that the solenoid II5 will be energized sufiiciently to -close the bleed valve I I4 when the rate of engine speed reaches a predetermined rate.

To summarize the discussion of this Fig. 6, a

source of vacuum is employed for cutting'off the supply. of fuel oil'at a desired point dependent upon .spee'dand'load conditions. Movement of the cut-off means (wedge block I 02) is effected in one direction by action of the suction against the pressure of the spring I06. When the suction is sufficiently reduced by bleeding air into the line II8, the spring I06 will move the block I02 toward the cut-off position. Bleed area and reduction of effective suction in the diaphragm chamber I05 is lowest at full-load and greatest at light-load, thus causing a slowermovement of the cut-off block I02 at 1ight-loadwhere any certain'linear travel makes a greater difference in percentage of power change, and vice versa.

Referring now to Fig. -'7, I show the application of my invention to a Diesel engine of the two-cycle type. In this arrangement, air for scavenging the cylinder and providing an explosive charge is supplied fromapump I23 to a header I24 from whence-it enters the cylinder a. Asiin other inventions of this type, fuel is injected from the pump chamber 89 into the heated compressed air in the cylinder, and is burned upon down-stroke of the piston. At the end of the down-stroke of the piston, air is admitted-at I24, the exhaust valve a being then opened, so'that the incoming air will not only force out the burned gases,-but during its upstroke (at which time the valve 85a is closed) the piston will compress said air to form a part of a new explosive mixture. In this instance-the diaphragm chamber I05 will have its suction pipe I I8 connected to the intake side I I9a of the pump I23 through a suction chamber I20a in which a constant suctional force is presentduring operation of the engine, as in the case of the suction chamber I20.

Theterm motive fluid is employed in a broad sense, in the accompanying claims, to include not only an air and gas or gasoline mix.- ture, but also the air admitted to a Diesel engine to form a combustible mixture with the oil, and steam for moving various types of steam engines.

The term load change in the accompanying claims refers to change in amount of work done or resistanceencountered at any given speed, whichnecessarily causes a change in engine speed until there is a change in the supply of motive fluid.

The term fluid'pressure as employedin certain of the claims is used in a broad sense to include either sub-atmospheric pressure or superatmospheric pressure. 7

I claim as my invention:

1. The combination with a prime 'mover and a source of motive fluidtherefor, of a valve for controlling the'fiow of motive fluid to the prime mover, an element operated by fluid pressure, for controlling movements of said valve, a bleed device which varies the effectiveness of said pressure inaccordance with changes/in the position of said element, and means responsive to a pre mover, an'element operated by fluid pressure, for

controlling movements of said valve, a graded bleed devicewhichvaries the effectivenessof said pressure, upon changes in the position of the valve, and means responsive'to changes in prime mover speed, for controlling flow in the bleed device. i

3. The combination with a prime mover and a source of motive fluidnth'e'refon'of a valve for controlling the flow of motive fluid to the prime mover, an'element operated by fluid pressure, for controlling movements of said valve, a bleed device' which varies the -effectiveness of said pressure in'accordance with changes in the position mined rate, for cutting off fiow inthe bleed'device. H

4. The combination with a prime mover and a source of motive fluid therefor, of a valve for controlling the flow of motive fluid to the prime mover, a suction-operated piston for moving the valve, a graduated bleed device for varying the extent of bleed in accordance with the position of said piston, and electrical apparatus which is energized 'by prime mover speed of a predetermined rate, for controlling the supply of air to the bleed device.

5. The combination with a prime mover and a source of motive fluid therefor, of a valve for controlling the flow of motive fluid to the prime mover, a fluid-pressure-operated piston for moving the valve, a graduated bleed device for varying the extent of bleed in accordance with the position of said piston, a normally-open valve controlling the supply of bleed air to said device, an electro-magnet for closing said valve, and an electrical device responsive to predetermined changes in prime mover speed for making and breaking the circuit of said magnet.

6. The combination with a prime mover and a source of motive fluid therefor, of a valve for controlling the flow of motive fluid to the prime mover, a fiuid-pressure-operated piston for moving the valve, a graduated bleed device for varying the extent of bleed in accordance with the position of said piston, a valve controlling flow of air at the bleed device, electrical apparatus which is energized by prime mover speed of a predetermined rate, for controlling movement of the second-named valve and hence the supply of air to the bleed device, a manually-operable element for moving the first-named valve, and a switch element associated with said element and controlling the circuit of said electrical apparatus, whereby the second-named valve can be caused to remain in fully open position during manual operation of the first-named valve.

7. The combination with a prime mover and a source of motive fluid therefor, of a valve for controlling the flow of motive fluid to the prime mover, means which yieldably urges the valve toward open position, an element which is operated through load changes, for moving the valve in opposition to the yieldable means, a device movable in predetermined relation to movements of said element, for varying the force exerted on said element by load changes, a manually-operable device for limiting the position to which the valve may be moved by the yieldable means, and means associated with said manual element, for rendering the automatic control elements ineffective to regulate the speed of the prime mover.

8'. The combination with an engine of the internal combustion type having an intake passageway provided with a throttle valve, of means responsive to changes in engine speed, for moving said valve to control the flow of motive fuel, an auxiliary fuel-supply line communicating with said passageway at a point between the throttle valve and the engine, and means responsive to changes in engine speed, for controlling flow through the auxiliary line.

9. The combination with an engine of the internal combustion type having an intake passageway provided with a throttle valve, of means responsive to changes in engine speed, for moving said valve to control the flow of motive fuel, an auxiliary fuel-supply line communicating with said passageway at a point between the throttle valve and the engine, and means more quickly responsive to changes in engine speed than .is the first-named means, for controlling flow through the auxiliary line.

10. The combination with an engine of the internal combustion type having an intake passageway provided with a throttle valve, of means responsive'to changes in engine speed, for moving said valve to control the flow of motive fuel, an auxiliary fuel-supply line communicating with said passageway at a point between the throttle valve and the engine, and means more quickly responsive to changes in engine speed than is the first-named means, for controlling flow through the auxiliary line, the said line being maintained open by its controlv means at normal running speeds, to admit fuel to the engine.

11. The combination with an engine of the internal combustion type having an intake passageway provided with a throttle valve, of means responsive to changes in engine speed, for moving said valve to control the flow of motive fuel, an auxiliary fuel-supply line communicating with said passageway at a point between the throttle valve and the engine, and means more quickly responsive to changes in engine speed than is the first-named means, 'for controlling flow through the auxiliary line, the said line being maintained open by its control means at normal running speeds, to admit fuel to the engine, and being closed as soon as the engine speed exceeds a predetermined rate.

12. The combination with an engine of the Diesel type, having a fuel inlet and an inlet line for combustion air, together with a pump element for injecting the fuel, of a device for moving said element, a fiuid-pressure-operated element which is movable to limit the travel of said device during its injection of fuel, and means responsive to load changes at any given speed of the engine, for varying the effectiveness of said pressure element.

13. The combination with an engine of the Diesel type, having a fuel inlet and an inlet line for combustion air, together with a pump element for injecting the fuel, of a device for moving said element, a fluid-pressure-operated element which is movable to limit the travel of said device during its injection of fuel, and means responsive to load changes at any given speed of the engine,

for varying the effectiveness of said pressure element in such manner that it will operate more rapidly at full loads than at light loads.

14. The combination with an engine of the Diesel type, having a fuel inlet and an inlet line for combustion air, together with a pump element for injecting the fuel, of a device for moving said element, a suction-operated element which is movable to limit the travel of said device during its injection of fuel, and means responsive to load changes at any given speed of the engine, for varying the effectiveness of said suction element, the suction element being energized by suction created in the air inlet.

15. The combination with an engine having an intake passageway provided with a throttle valve -for controlling the flow of .motive fluid to the engine, of a conduit leadingfrom the passageway at a point between the valve and the engine, a. device actuated by fluctuations of the suctional force that are transmitted through said passageway, and having operative connection with the valve for moving the same in response to said fluctuations, and a fluid-containing reservoir communicating with the conduit, to supply limited quantities of dampening fluid thereto for periods of short duration.

16. The combination with an engine having an intake passageway provided with a throttle valve for controlling the flow of motive fluid to the engine, of a conduit leading from the passageway at a point between the valve and the engine, a device actuated by fluctuations of the suctional force that are transmitted through said passageway, and having operative connection with the valve for moving the same in response to said fluctuations, a fluid-containing reservoir communicating with the conduit, to supply limited quantities of dampening fluid thereto for periods of short duration, and a valve for regulably restricting the rate of flow between the reservoir and the conduit.

GEORGE E. HOWARD. 

